[Python-Dev] A little GC confusion

[Michael Hudson]

Kevin Jacobs <jacobs@penguin.theopalgroup.com> writes:

> I doesn't have any time to really look at your code, but I thought I'd point
> out a trick that several extension modules use to protect statically
> allocated type objects.  Here is the code from socketmodule.c:
> 
> /* static PyTypeObject PySocketSock_Type = {
> .
> .
> .
>         0,      /* set below */                 /* tp_alloc */
>         PySocketSock_new,                       /* tp_new */
>         0,      /* set below */                 /* tp_free */
> };
> 
> /* buried in init_socket */
>         PySocketSock_Type.tp_alloc = PyType_GenericAlloc;
>         PySocketSock_Type.tp_free = _PyObject_Del;
> 
> This trick ensures that the static type object is never freed.

Um, I think you'll find this is because PyType_GenericAlloc &
_PyObject_Del aren't compile-time constants when _socket is
dynamically linked (they're defined in a different dll).

Cheers,
M.

-- 
  > so python will fork if activestate starts polluting it?
  I find it more relevant to speculate on whether Python would fork
  if the merpeople start invading our cities riding on the backs of 
  giant king crabs.                 -- Brian Quinlan, comp.lang.python